JPH09138666A - Moving picture correcting method and moving picture correcting device for display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent picture quality from being degraded by making the visual deviation of display at the time of displaying a moving picture small. SOLUTION: In a PDP 14 time-sharing one frame into plural subfields SF 1-SFn (for example, n=4) and displaying a multilevel picture while lighting subfields corresponding to a luminous level, this device is provided with a movement detecting circuit 22 detecting the moving direction and the moving amount of moving pixels between frames and a display position correcting circuit 20 outputting display positions of plural subfields SF1-SFn to the side of the PDP 14 while correcting the display positions every frame based on the detection output of the detecting circuit 22. Then, since this device can place the display positions of the subfields SF1-SFn on loci of a human seeing the moving pixels by correcting the display positions of the plural subfields SF1-SFn every frame according to the moving direction and the moving amount of the moving pixels, the picture quality is prevented from being degraded by making the visual deviation of display small while narrowing the deviation width between subfields at the time of displaying the moving picture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention time-divides one frame into a plurality of subfields (or subframes), and emits a subfield corresponding to the luminance level of an input video signal to display a multi-gradation image. The present invention relates to a moving image correction method for a display device and a moving image correction device.

[0002]

2. Description of the Related Art Recently, as a thin and lightweight display device, P
Attention has been focused on DP (plasma display panel) and LCDP (liquid crystal display panel). The driving method of this PDP is completely different from the conventional CRT driving method, and is a direct driving method using a digitized input video signal. Therefore, the luminance gradation emitted from the panel surface is determined by the number of bits of the signal to be handled.

[0003] PDPs are AC type and D type having different basic characteristics.
It is divided into two types of C type. In the AC type PDP, sufficient characteristics have been obtained with respect to luminance and life, but as for gradation display, only a maximum of 64 gradation display has been reported at the prototype level, but the address / display separation type driving method (ADS) A method of 256 gradations in the future by the subfield method has been proposed. The drive sequence and drive waveform of the PDP used in this method are shown in FIGS.

In FIG. 3A, for example, 8 bits,
In the case of 256 gradations, one frame has a relative luminance ratio of 1,
Eight subfields SF1, SF2, SF3, SF4, SF5, S of 2, 4, 8, 16, 32, 64, 128
The display is composed of F6, SF7, and SF8, and displays 256 gradations by combining the luminances of eight screens.

In FIG. 3B, each subfield is composed of an address period for writing refreshed data for one screen and a sustain period for determining the luminance level of the subfield. In the address period, first, wall charges are initially formed on each pixel at the same time for the entire screen, and then a sustain pulse is applied to the entire screen to perform display. The brightness of the subfield is proportional to the number of sustain pulses and is set to a predetermined brightness. In this way, 256 gradation display is realized.

[0006]

The display device of the address / display separation type driving system as described above has been conventionally shown in FIG.
The video signal input to the input terminal 10 is converted by the data conversion circuit 12 into display data time-divided into a plurality of sub-frames SFn to SF1 for each frame, and is output to the PDP 14. The PDP 14 displays a multi-tone image. However, in the conventional example shown in FIG. 4A, no special processing for correcting the image at the time of displaying the moving image is performed, and the moving image display and the still image display are performed by the similar driving method. However, when displaying a moving image, there is a problem in that a visual display shift is widened in the moving direction of the moving image and the image quality is significantly deteriorated.

That is, for convenience of explanation, as shown in FIG. 4B, one frame includes four subfields SF4 to SF4.
PD that performs time division to SF1 and displays 4 bits and 16 gradations
In P14, the brightness level 1 input to the input terminal 10
Consider a case where moving pixels related to five video signals are moving in a predetermined direction (for example, the upper direction of the screen) at a rate of five dots per frame. In the conventional example of FIG. 4A, since the display position of the subfields SF4 to SF1 of each frame is the same pixel (for example, the same dot) on the screen in the same frame, the subfields SF4 to SF1 of each frame are displayed.
FIG. 5 conceptually shows the relationship between the light emission time (horizontal axis) and the display position (light emitting position) of the moving pixel on the screen of the PDP 14 (vertical axis).

In FIG. 5, the rectangles are arranged in descending order of 8, 4,
Subfields SF4, SF3,
SF2 and SF1 are shown, and a rectangle with a hatching line rising to the right indicates a sub-field S in each frame that emits light.
Represents F4 to SF1. Lines A and B running diagonally are
It shows a locus where a human follows the movement of dots with eyes (because the visual sense has a property of gazing at a moving object), and indicates that the maximum displacement width ZM of display displacement is large.

The maximum deviation width ZM is proportional to the moving speed of the moving pixel, and varies depending on the luminance level (lighting level). Also, in the case of monochrome display, the above-mentioned display shift appears as "blurring", and in the case of color display, since there is a level difference between each color, the respective shift widths are different and appear as color shift (color pseudo contour). ).

The present invention has been made in view of the above-mentioned problems, and one frame is time-divided into a plurality of subfields, and a subfield corresponding to the luminance level of an input video signal is emitted to emit a multi-gradation image. In the display device that displays
An object of the present invention is to provide a moving image correction method for a display device and a moving image correction device, which can prevent visual deterioration occurring when displaying a moving image and prevent deterioration of image quality.

[0011]

According to the moving image correction method of the present invention, one frame is time-divided into a plurality of sub-fields, and the sub-fields corresponding to the luminance level of the input video signal are emitted to emit multiple gradations. A display device for displaying an image is characterized by detecting a moving direction and a moving amount of a moving pixel between frames, and correcting display positions of a plurality of subfields of each frame based on the detected output.

One frame consists of n subfields SFn
Considering the case of time-division into SF1 to display a multi-gradation image of an n-bit input video signal, the moving direction (for example, the upward direction of the screen) and the moving amount (for example, 5 per frame) of moving pixels between frames. Dot) and based on this detection output, n subfields SFn of each frame are detected.
~ Correct the display position of SF1. In this way, the display positions of the subfields SFn to SF1 are corrected according to the moving direction and the moving amount of the moving pixel for each frame, so that the subfields SFn to SFn on the trajectory of the human eye viewing the moving pixel.
The display position of F1 can be placed.

The moving image correction apparatus according to the invention of claim 2 is
In a display device that time-divisions a frame into a plurality of subfields and emits a subfield corresponding to the brightness level of an input video signal to display a multi-gradation image, movement of moving pixels between frames based on the input video signal. A motion detection circuit that detects a direction and a movement amount, and a display position correction circuit that corrects the display positions of a plurality of subfields of each frame based on the detection output of the motion detection circuit and outputs the corrected display position to the display device side are provided. It is characterized by

By providing the motion detection circuit and the display position correction circuit, the display positions of the subfields SFn to SF1 are corrected according to the moving direction and the moving amount of the moving pixel for each frame. A device for implementing the inventive method can be constructed simply.

According to a third aspect of the present invention, in the second aspect of the invention, the display position correction circuit uses the detection output of the motion detection circuit as an address and outputs the data obtained by correcting the display positions of a plurality of subfields of each frame. Since it is configured by the ROM, the display position correction circuit having a desired function can be easily configured.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a moving image correction method for a display device and a moving image correction device according to the present invention. In FIGS. 1A and 1B, the same parts as those in FIGS. In FIG. 1A, 10
Is an input terminal to which an n-bit video signal is input. The input terminal 10 has a display position correction circuit 20 and a motion detection circuit 2.
The input side of 2 is coupled, and the output side of the display position correction circuit 20 is coupled with the PDP 14 as a display device.

The motion detection circuit 22 has the input terminal 1
The moving direction and the moving amount of the moving pixel of the current frame screen in the PDP 14 are detected based on the video signals of the current frame and the previous frame input to 0. The display position correction circuit 20 receives the n-bit video signal input to the input terminal 10 from the subfields SFn to SFn.
A data conversion circuit 12 for converting display data of SF1;
And a ROM 24. In this ROM 24,
Data detected by correcting the display position of each subfield of the display data output from the data conversion circuit 12 to the display position corresponding to the moving direction and the moving amount of the moving pixel is output by using the detection output of the motion detecting circuit 22 as an address. It is preset and stored as data.

Next, the operation of FIG. 1 will be described with reference to FIG. For convenience of explanation, as shown in FIG.
One frame is time-divided into four subfields SF4 to SF1 (that is, n = 4), and in the PDP 14 that displays 4 bits and 16 gradations, the moving pixels related to the input video signal of the brightness level 15 are 5 in one frame. Consider a case where the dots are moving in a predetermined direction (for example, an upward direction of the screen).

In this case, the motion detecting circuit 14 determines, based on the video signals of the current frame (for example, the second frame) and the previous frame (for example, the first frame) input to the input terminal 10, the moving pixels of the current frame screen in the PDP 14. The moving direction (for example, the upper direction of the screen) and the moving amount (5 dots / frame) are detected.

Data conversion circuit 1 of display position correction circuit 20
2 converts the video signal input to the input terminal 10 into display data of four subfields SF4 to SF1 for each frame. When the brightness level of the input video signal is 15,
All of the subfields SF4 to SF1 are converted into display data that emits light (lights up). That is, the weight of luminance is 8 + 4 + 2 + 1 = 15. When the brightness level of the input video signal is 10, the subfields SF4 to
SF4 and SF2 of SF1 are converted into display data for emitting light, and the weight of luminance is 8 + 2 = 10.

The ROM 24 of the display position correction circuit 20 uses the detection output of the motion detection circuit 22 as an address and the subfield SF4 of the display data output from the data conversion circuit 12.
The data obtained by correcting the display positions of -SF1 to the display positions shown by the upward-sloping hatching lines in FIG. 2 is output to the PDP 14. The data corresponding to the address stored in advance in the ROM 20 is set as follows.

When the moving direction of the moving pixel is the upper direction of the screen and the moving amount is 5 dots / frame, on the locus shown by the diagonal solid lines a and b in the conceptual diagram shown in FIG. Data in which the display positions of the subfields SF4 to SF1 are corrected are set so that the light emission of the subfields SF4 to SF1 is on the locus). That is, the display position of the subfield SF4 is moved upward (the vertical axis direction in the drawing) by 0 dots (that is, not moved), and the subfield SF3 is moved by 2 dots upward. However, for the sub-fields SF2 and SF1, the corrected display data for moving the display position upward by 3 or 4 dots is set. Therefore, the maximum displacement width zm of display displacement can be reduced to half or less of the conventional example (ZM), and “blurring” in monochrome display and color displacement (color pseudo contour) in color display are suppressed. be able to.

In the above embodiment, the moving direction of the moving pixel is set to the upward direction on the screen and the moving amount is set to 5 dots / frame, but the present invention is not limited to this. For example,
When the moving direction of the moving image element is upward and the moving amount is 8 dots / frame, the subfields of each frame are arranged so that the light emission of the subfields SF4 to SF1 is placed on the locus shown by the diagonal dotted lines c and d in FIG. The display positions of SF4 to SF1 are corrected. That is, for the sub-field SF4, its display position is moved upward by 0 dot, the sub-field SF3 is moved upward by 3 dots, and the sub-fields SF2 and SF1 are moved upward by 5 display positions, respectively. Perform correction by moving 6 dots.

Other movement amounts (for example, 4 dots / frame, 7 dots / frame, etc.) are similarly set and stored. Also, when the moving direction is other than the upward direction of the screen (for example, right direction or diagonal direction),
The movement amounts are similarly set and stored.

In the above embodiment, the motion detecting circuit detects the moving direction and the moving amount of the moving pixel in the input video signal of the current frame based on the input video signals of the current frame and the previous frame. The present invention is not limited to this, and may be any one that detects the moving direction and the moving amount of the moving pixel between frames.

In the above embodiment, the display position correction circuit is composed of the data conversion circuit and the ROM.
The present invention is not limited to this, and it is sufficient that the display positions of a plurality of subfields of each frame are corrected based on the detection output of the motion detection circuit and output to the PDP side. That is, the data conversion circuit may not be provided, and a configuration other than the ROM may be used to correct the display positions of the plurality of subfields of each frame based on the detection output of the motion detection circuit and output the corrected subfields to the PDP side. . If the display position correction circuit does not include a data conversion circuit, the display position correction circuit and the P
A data conversion circuit may be provided between the DPs or in the PDP.

In the above-described embodiment, the case where the display device is a PDP has been described, but the present invention is not limited to this, and can be applied to the case where a digital display device (for example, LCDP) is used.

[0028]

As described above, the moving image correction method according to the first aspect of the invention is
In a display device that time-divisions one frame into a plurality of subfields SFn to SF1 and emits a subfield corresponding to the brightness level of an input video signal to display a multi-gradation image, a moving direction of moving pixels between frames Since the movement amount is detected and the display positions of the plurality of subfields SFn to SF1 of each frame are corrected based on the detection output, the movement of the subfields SFn to SF1 on the trajectory of the human eye observing the moving pixels. You can put the display position.
For this reason, it is possible to reduce a visual shift between the sub-fields when displaying a moving image to reduce a visual shift and prevent deterioration of image quality.

The moving image correction apparatus according to the invention of claim 2 is 1
In a display device that time-divisions a frame into a plurality of subfields and emits a subfield corresponding to the brightness level of an input video signal to display a multi-gradation image, movement of moving pixels between frames based on the input video signal. A motion detection circuit that detects a direction and a movement amount, and a display position correction circuit that corrects the display positions of a plurality of subfields of each frame based on the detection output of the motion detection circuit and outputs the corrected display position to the display device side are provided. Accordingly, the subfields SFn to SFn are changed according to the moving direction and the moving amount of the moving pixel for each frame.
Since the display position of No. 1 is corrected, the device for carrying out the method of the present invention can be easily constructed.

According to a third aspect of the present invention, in the second aspect of the present invention, the display position correction circuit uses the detection output of the motion detection circuit as an address and outputs data obtained by correcting the display positions of a plurality of subfields of each frame. Since it is configured by the ROM, the display position correction circuit having a desired function can be easily configured.

[Brief description of the drawings]

1A and 1B show an embodiment of a moving image correction method for a display device and a moving image correction device according to the present invention, wherein FIG. 1A is a block diagram of the device, and FIG. It is an explanatory view of a sequence.

FIG. 2 is a diagram conceptually explaining the operation of FIG.

FIG. 3 illustrates a subfield lighting method,
(A) is an explanatory view of a drive sequence in the method of 256 gradations, (b) is a drive waveform diagram.

4A and 4B show a conventional example, FIG. 4A is a block diagram of a device, and FIG. 4B is an explanatory diagram of a drive sequence in 16 gradation display by a subfield method.

FIG. 5 is a diagram conceptually explaining the operation of FIG.

[Explanation of symbols]

10 ... Input terminal, 12 ... Data conversion circuit, 14 ... PD
P (an example of a display device), 20 ... Display position correction circuit, 2
2 ... Motion detection circuit, A, B, a, b, c, d ... Straight line representing a locus for following the dot movement with eyes, SF1 to SF4 ... Subfields, ZM, zm ... Maximum deviation width.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Junichi Onodera 1116 Suenaga, Takatsu-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu General Co., Ltd. 72) Inventor Seiji Matsunaga 1116 Suenaga, Takatsu-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu General Co., Ltd.

Claims (3)

[Claims] 1. A display device for time-division of one frame into a plurality of sub-fields, which emits a sub-field corresponding to the luminance level of an input video signal to display a multi-gradation image. A moving image correction method for a display device, comprising detecting a direction and a movement amount, and correcting display positions of a plurality of subfields of each frame based on the detected output. 2. A display device which time-divisions one frame into a plurality of subfields and emits a subfield corresponding to a luminance level of an input video signal to display a multi-gradation image, based on the input video signal. A motion detection circuit that detects the moving direction and the moving amount of the moving pixel between frames, and corrects the display positions of a plurality of subfields of each frame based on the detection output of this motion detection circuit and outputs the corrected subfield to the display device side A moving image correction device for a display device, comprising: a display position correction circuit. 3. The display position correction circuit uses the detection output of the motion detection circuit as an address, and uses the data obtained by correcting the display positions of a plurality of subfields of each frame as output data.
The moving image correction device for a display device according to claim 2, comprising M.